Eeew. Only time will tell, but it sounds like a load of crap. (couldn’t resist).
According to a study commissioned by NASA, a crew of six astronauts would generate six tons of solid waste during a two-year trip to Mars. In "Harnessing the Power of Poop," SPACE.com says that NASA scientists have identified a bacteria, the Geobacter, found in the
Potomac riverin 1987, which could transform this waste into electricity. The bacteria would live in a membrane microbial fuel cell. There, they would catch electrons from human waste and produce electricity for use aboard a spacecraft or on a Martian colony. When these fuel cells pass the development stage, they would potentially be used on Earth, in our own homes, by recycling our own organic waste.